1. Field of the Invention
This invention relates to a roller, provided at a downstream side of a coloring unit for jetting a colorant out and onto a top of an outer surface of an electric wire moving along a lengthwise direction of the electric wire a coloring apparatus The roller has a pair of tapered surfaces touching the outer surface of the electric wire and converge toward one another as they near a rotating axis.
2. Description of the Related Art
Various electronic apparatuses are installed in an automobile. The electronic apparatuses are typically wired with a wiring harness for transmitting electric power from a power supply, or control signals from a computer. The wiring harness includes a plurality of electric wires and a connector jointed to ends of the electric wires. The electric wire has a conductive core wire and a cover made of insulative synthetic resin for covering the core wire. The electric wire is a so-called covered wire.
The electric wires are required to be distinguished with regard to a size of the core wire, a material of the cover (change of the material by existence of heat-resistance) and applications. The applications are, for example, for an airbag, an ABS (Antilock Brake System) or a system in the automobile, in which electric wires for transmitting control signals such as information of a car speed or a power transmission system are used.
The electric wires of the wiring harness include a mark on each outer surface to distinguish the applications (systems). A wire coloring apparatus 100 for applying a mark is shown in FIG. 7. The coloring apparatus 100 is an apparatus for putting a mark 400 at a part of an outer surface 300a of an electric wire 300, as shown in FIG. 7.
The wire coloring apparatus 100, as shown in FIG. 7, includes a coloring nozzle 104 located between the guide roll 102 and a forwarding roller 103, and a duct 105.
Reference numeral 101 in the figure corresponds to a frame. The frame 101 is installed, for example, on a floor of a factory. The frame 101 extends horizontally. The guide roll 102 is arranged rotatably at one end of the frame 101. The guide roll 102 winds a long electric wire 300 prior to marking. The guide roll 102 supplies the electric wire 300 toward the coloring nozzle 104 and the duct 105.
A pair of forwarding rollers 103 is arranged at the other end of the frame 101. The pair of forwarding rollers is supported rotatably by the frame 101, and aligned in a direction vertical to the floor. The pair of forwarding rollers 103 in FIG. 7 is aligned in a direction that is vertical to the floor, but can be aligned horizontally. The forwarding rollers 103 are rotated in opposite directions to each other at a same rotating speed by a motor (not shown). The pair of forwarding rollers 103 catches the electric wire 300 therebetween, and pulls the electric wire 300 from the guide roll 102 along a lengthwise direction of the electric wire 300. Thereby, the electric wire 300 moves from the guide roll 102 toward the forwarding roller 103 along an arrow K in FIG. 7.
The coloring nozzle 104 jets a colorant 500 toward the outer surface 300a of the electric wire 300. The duct 105 is arranged at a side of the forwarding roller 103 from the coloring nozzle 104 in the wire coloring apparatus 100 and between the coloring nozzle 104 and the forwarding roller 103. The duct 105 is for drying the colorant put on the outer surface 300a of the electric wire 300. The duct 105 is formed into a tube-shape for passing the electric wire 300 inside thereof. A drawing unit (not shown) like a vacuum pump is connected to the duct 105. The drawing unit draws a gas in the duct 105 to prevent filling a solvent and a dispersant in the colorant 500 outside the wire coloring apparatus 100. Patent Document 1 is the Japan Published Patent Application No. 2004-15722.